MANILA (REUTERS) - Three UCLA basketball players detained in China on suspicion of shoplifting were headed back to the United States on Tuesday (Nov 14) after US President Donald Trump said he had sought the help of Chinese President Xi Jinping in the case.

Staff for Delta Air Lines confirmed that the players had boarded a Delta flight from Shanghai to Los Angeles.

"What they did was unfortunate," Trump told reporters earlier in Manila. He said the trio, who have been held since last week, could have faced long prison sentences, and described Xi's response as "terrific".

"They're working on it right now," Trump said.

Trump had raised the issue with Xi during a dinner held during the US leader's Nov 8 to 10 state visit to Beijing. Trump was in the Philippines capital for a summit of Asian leaders.

Asked about the trio and Trump's discussing the issue with Xi, China Foreign Ministry spokesman Geng Shuang told a daily news briefing in Beijing he was unable to provide any further information.

The three basketball players from the University of California, Los Angeles (UCLA) were detained by police on Nov 7 in the eastern Chinese city of Hangzhou over allegations of shoplifting. They were not on the team's return flight to the United States on Saturday.

A senior White House official said the players had been given relatively light treatment due to Trump's intervention.

"It's in large part because the President brought it up," the official told Reuters.

The UCLA team had been in China for a game against Georgia Tech in Shanghai on Saturday, which UCLA won 63-60. The teams had travelled to Hangzhou earlier in the week to visit the headquarters of the game's sponsor, Chinese tech giant Alibaba Group Holding.

The three students - freshmen LiAngelo Ball, Cody Riley and Jalen Hill - were taken in for questioning by police about alleged shoplifting from a Louis Vuitton store.

They were released from police custody early on Wednesday and had been confined to a luxury hotel pending legal proceedings.

Pac-12 Commissioner Larry Scott, who had not spoken with the three players, said what had occurred was a "very regrettable situation".

Pac-12 is a college athletic conference in which UCLA participates.

"I'm just glad it's resolved and that they're on the way home safely," he told Reuters by telephone from an Anti-Defamation League Sports Leadership Council event in San Francisco.

Since the matter did not occur on the court, it was up to UCLA whether the players would be punished, Scott said.